Engines are devices to generate mechanical power by combusting fuel. Engines may include 2-stroke cycle engines, 4-stroke cycle engines, rotary engines, etc. according to an operating method. An engine may be provided with an oil pump for circulating a lubricant and a relief valve for preventing the pressure of the lubricant ejected from the oil pump from being overly increased.
Transmissions are devices to convert the power generated by an engine to a rotation force according to a speed and transfer the rotation force to other parts. Transmissions may include manual transmissions, in which a speed change process is manually performed by a driver, and automatic transmissions, in which the speed change process is automatically performed according to a certain pattern. Among these transmissions, an automatic transmission may include torque converters, operating mechanisms, planetary gear devices, electronic control devices, hydraulic control mechanisms, etc. A hydraulic control mechanism is provided with a hydraulic control valve for constantly maintaining an oil pressure in the automatic transmission.
Solenoid valves are devices to supply oil to a specific location or control the pressure of the supplied oil, that is, a hydraulic pressure, by being automatically opened or closed according to the application of electric power. The solenoid valve is used as a relief valve of the oil pump or a hydraulic control valve of a hydraulic control mechanism, and may be classified into a spool type, a ball type, or a poppet type according to an internal structure.
Korean Patent Publication Nos. 2011-0110204 (2011.10.06.) and 2012-0101319 (2012.09.13.) disclose various types of solenoid valves.
The former solenoid valve may include a value for controlling oil and a solenoid for operating the valve. A connector that is a power connection part is provided on an upper end of the solenoid.
The above-described solenoid valve has a structure in which the valve is inserted in a device (engine or transmission). In other words, since the solenoid and the connector are exposed to the outside of the device during installation of the solenoid valve, foreign substances containing water may flow into the solenoid via the connector. In particular, when an opening part of the connector faces upward, raindrops flowing down along a lead wire connected to the connector may be easily flow into the solenoid.
The above problem may be identically applied to the latter hydraulic valve, in which the connector protrudes from a lateral side of the solenoid, and thus a structure to prevent intrusion of the foreign substances containing water is needed.
Furthermore, in a conventional solenoid valve (hydraulic valve), since at least part of the device protrudes to the outside of the device as described above, space for coupling and separation of the connector is needed. Accordingly, a layout design of an engine room may be difficult.